如何提高最低成本路径模型的模拟速度

Question

通过使用网络扩展，下面的代码在两个多边形(由几个补丁组成)之间构建成本最低的路径：

to calculate-LCP [ID-polygon-1 ID-polygon-2] 
let path []
let path-cost -1

;;;;;;;;;;;;;;;;;;;;;;;;
;; Define polygon edges
ask patches with [plabel != ID-polygon-1] [
 ask neighbors with [plabel = ID-polygon-1] [
  ask nodes-here [
    set color red ] ] ]

ask patches with [plabel != ID-polygon-2] [
 ask neighbors with [plabel = ID-polygon-2] [
  ask nodes-here [
    set color red ] ] ]

;;;;;;;;;;;;;;;;;;;;;;;;
;; Build least-cost path
ask nodes with [color = red] [
 foreach sort nodes-on patches with [ID-polygon = ID-polygon-1] [ 
  let node-on-polygon-1 ?  
  foreach sort nodes-on patches with [ID-polygon = ID-polygon-2] [ 
   let node-on-polygon-2 ? 

   ask node-on-polygon-1 [ 
    let cost nw:weighted-distance-to node-on-polygon-2 "link-cost" 
    if path-cost = -1 or cost < path-cost [ 
     set path-cost cost 
     set path nw:weighted-path-to node-on-polygon-2 "link-cost" ] ] ] ] ] 

;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Draw least-cost path
foreach path [ ;; trace le least-cost path 
  ask ? [ set color red
    set thickness 0.2 ] ]
end 

我将这段代码应用于图中用黑色矩形表示的两个多边形。通过使用profiler扩展，此代码运行了14分钟。

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对于每一只狼，我想在有一只狼的多边形和位于狼周围3公里半径内的所有多边形之间建立成本最低的路径。下面是我的代码：

ask wolves [ 
 set my-list-of-polygons-in-buffer ( [plabel] of patches in-radius 3 ) 
 set my-list-of-polygons-in-buffer remove-duplicates my-list-of-polygons-in-buffer 
 set my-list-of-polygons-in-buffer remove [plabel] of patch-here my-list-of-polygons-in-buffer 
 set my-list-of-polygons-in-buffer remove "" my-list-of-polygons-in-buffer 

 foreach my-list-of-polygons-in-buffer [ 
 let ID-polygon-in-buffer ?

  ask patches with [plabel = ID-polygon-in-buffer] [ 

   let LCP calculate-LCP [my-ID-polygon] of myself ID-polygon-in-buffer ] ] ]

问题是，我的过程"calculate-LCP“运行太慢，无法在wolves周围的缓冲区中定义最低成本的路径(我的模型中有100条wolves )。如何提高模型的模拟速度？

非常感谢你的帮助。

Answer 1

在第一次设置网络时，您只需调用nw:set-snapshot turtles links一次。如果任何权重发生更改，或者添加或删除了任何链接或节点，则需要再次调用它。这应该会极大地加速你的代码。